Can I use a secondary HDD from one system on another?

[Dragomatic]

So my current build (only my second, still very new to computer building) has a single 1 TB HDD that runs a non-genuine version of Windows 7. I recently got a second 1 TB and plan on purchasing a 120 GB SSD along with a legal copy of Windows 8.1 to install on the SSD. Now I was planning on wiping the first HDD and starting from scratch on that one, but for the second one, can I put files on there from my current system (loads of documents, videos, and etc.) and use that HDD with the new legal system without issue? Or will using it with a new system require me to reformat the drive and lose everything?

 

[BlazeMike]

How big are the files on your first hdd?

The easiest way is to get a pendrive or portable HDD transfer you important files from you current build.... Wipe the first hdd and start over..

The OS shouldn't be a problem, i see where ur going....

Just to be on the safer side the portable hdd / pendrive option should be good..

PLease state the capacity of the first hdd and the amount of space it occupies...

Is the non genuine win 7 installed on the same first hdd?

 

[Dragomatic]

Both the first and second HDD's are 1TB, and the amount of data I'd like to save for the new system is probably around 50-75 GB's, not sure what the exact amount will be but definitely around those numbers and therefore higher than most thumb drives. And yes the non genuine win7 is on the first HDD, the plan was to wipe that drive anyway and use the second drive for holding the files temporarily